Field trials were conducted in North Carolina and Virginia to compare the efficacies of three WideStrike cotton varieties along with that of their non-Bt sister line under insecticide-treated and non-treated conditions. A Bollgard II variety was included in the NC study for additional comparison. Each trial was evaluated on three dates for the percentage of bolls with a live larva and/or damage for each variety. In NC, larval numbers in the non-sprayed non-Bt were highere than that of any other treatment combination on two of three dates. Boll damage levels followed a similar trend where non-sprayed non-Bt sustained significantly higher levels of damage compared to other treatment combinations on all sample dates. WideStrike varieties performed similarly among themselves and in comparison to Bollgard II, although Bollgard II had numerically lower levels of damage than each WideStrike variety on all sample dates. In VA, larval densities did not differ among treatment combinations on any sample date. However, boll damage levels differed on the last of the three sample dates, as both insecticide-sprayed and non-sprayed non-Bt sustained significantly more boll damage compared to other treatment combinations. No differences were observed among the WideStrike varieties with regard to bollworm efficacy. These results demonstrate that neither WideStrike nor Bollgard II varieties should require insecticide sprays for bollworm under low-to-moderate infestation levels in the NC-VA region.